A variety of heaters have been used for the sake of heating or warming. In particular, in recent years, a sheet-like heating element which uses carbon fiber attracts a lot of attention for the use as a heating element which radiates a far infrared ray. Concerning such as a carbon fiber sheet-like heating element, a variety of carbon fiber sheet-like heating elements are being proposed and used.
Such a carbon fiber sheet-like heating element is known to emit a far infrared ray. The far infrared ray is a kind of magnetic waves and has a wavelength of 8˜16 μm which is most useful for a human body. When the far infrared ray is absorbed by the human body, it penetrates up to a deep skin layer (4˜5 cm) which is 80 times deeper than common heat, thus causing oscillation with about 2,000 vibrations per minute which is very fine vibrations, thus enhancing the activity of cells. During the above cell activity procedures, heat energy is generated, and the temperature of the human body increases, and microvessel expands, and blood circulation becomes activated, so the thrombus in blood vessels melts, and the blood circulation is enhanced, and blood becomes clear, and ph is increased, and a function for changing a body constitution changes from acid constitution to weak alkali constitution is strengthened, and spiritual health is relaxed, and a stress which is a cause of adult diseases may be reduced. For this, there is a lot of efforts to use such a far infrared ray. As one example of such efforts, a carbon fiber sheet-like heating element may be regarded as such an effort.
In the carbon fiber sheet-like heating element, a carbon fiber is formed in a shape of sheets by means of a forming function substance, for example, a resin, etc. so as to stabilize the fiber structure. Since the carbon fiber sheet-like heating element emits a high temperature heat, it is not preferred to use a combustible substance like a resin, but it is inevitably used as a surface stabilizer which is capable of stabilizing the carbon fiber in a sheet-like form. As the above-mentioned surface stabilizer, a combustible resin is not used, and instead a resin with a heat resistance is selected. Since the main use of such a carbon fiber sheet-like heating element is heating or warming, a lot of developments are focused on its heating characteristic and electric characteristic.
For the carbon fiber sheet-like heating element, the research is focused on the aspect of heating performance; however no research on the aspect of the radiation of the far infrared ray element is being performed. Such a far infrared ray radiation element has been used for the sake of heat therapy. for this, it needs to selectively and efficiently radiate far infrared ray having a specific wavelength region based on the purpose of use.
Among such developments, there is the Korean patent registration number 10-199636 whose title is “far infrared radiation element and method for radiating far infrared ray” which has improved a lot of the problems; however the emission amount of the far infrared ray is small, and the organic compound layer is bent, which results in a lot of defective products.